How Deep Is Lake Michigan?

At its deepest point, Lake Michigan has a depth of 925 feet. On average, however, the lake has a depth of approximately 279 feet. As of 2014, Lake Michigan is the third largest Great Lake in North America with a water surface area of 22,300 square miles.

The lake borders the four U.S. states of Indiana, Illinois, Wisconsin and Michigan. Its southernmost point leads into the city of Chicago, while the city of Milwaukee is located on its southwestern shore. The lake was first discovered by Jean Nicolette as part of an expedition seeking the Northwest Passage in 1634. Between July and August, the temperature of Lake Michigan averages around 60 to 70 degrees Fahrenheit.